The invention relates to a commutation circuit for thyristors, in general, and more particularly to a circuit of the soft commutation type.
An auto-commutation circuit is described in "Principles Of Inverter Circuits" by B. D. Bedford and R. G. Hoft (John Wiley & Sons 1964) on page 185, FIG. 7.16. In the impulse-commutated inverter there described, auto-commutation is achieved in a push-pull fashion between the thyristors connected at the far ends of a center-tapped primary winding of the output transformer of the inverter, through respective feedback rectifiers from such primary winding. The commutation process in this circuit includes two sides of the transformer primary windings and requires hard commutation; the main drawback of such commutation circuit is its input frequency limitation.
An object of the present invention is to provide a commutation circuit of improved range in its frequency of operation.
Another object of the present invention is an improved commutation circuit which is of the single-pole type and therefore of lower cost.